I don't see how that could be anywhere near harassment. If that's the case we all get harassed daily with hundreds of spam emails. I don't remember any lawsuits against spammers on basis of harassment.
From reading the article, the phrase "bordering on harassment" came about when a single individual sent 22 emails within a 2-day timespan. (Perhaps they forgot to take their meds?) It makes no sense to compare this to a collection of spam from various, automated sources. If I were that engineer, I'd have had similar thoughts. I realize the squeaky wheel gets the grease, but at some point you'd think a neuron would fire to make them ask themselves "does sending another email this hour really help?"
Heh, have you ever worked in Sales? This is a highly effective technique for getting what you want from your suppliers or people you are waiting on (obviously not customers). People deal with the issue or have to put up with your frequent interruptions. They usually rush to do the former.
If my family's income depended on getting the money I made from Apple, I'd be doing a lot more than sending 22 e-mails. It might be tricky if you're in Europe, but legal action is certainly appropriate in this case.